Vulcanizer



Dec. 17, 1929. w. M. Fos'r 1,740,034

` y VULGANIZER Filed July 50. 1927 www Patented Dec. 17, 1929 PATENT OFFICE WILLIAM M. POST, OF I-IOOI) RIVER, OREGON VULCANIZER Application led July 30,

This invention relates to vulcanizers and more particularly to a device for vulcanizing dental plates and the like.

An important object of the invention is to provide a vulcanizer of the type referred to which is efhcient in operation and which may be operated with the utmost safety.

A further object is to provide a device of t-he above mentioned character which is adapted to receive varying numbers of flasks.

A further object is to provide means for permitting expansion of the material being vulcanized without causing damage to the parts of the device.

A further object is to provide a vulcanizer which is adapted for use in connection with different materials which are vulcanized at different pressures and temperatures.

A further object is to provide a device of 20 the character referred to which is convenient to use and wherein the loss of heat during the operation of the device is minimized.

A further object is to provide a cradle forV receiving the flasks which are clamped together during t-he vulcanizing operation, and wherein novel means is provided for preventing the rotation of the flask supporting cradle during the clamping operation.

Other objects and advantages of the inven- 30 tion will become apparent during the course of the following description.

Tn the drawings T have shown one embodiment of the invention. In this showing,

Figure 1 is a perspective view of the de- 5 vice,

Figure 2 is a cent-ral vertical sectional view,

Figure 3 is a horizontal section on line 3-3 of Figure 2, and,

Figure 4 is a detail section on line 4-4 40 of Figure 3.

Referring to the drawings, the numeral 10 designates a preferably cylindrical casing supported at its lower end on legs 11 to space the bottom 12 above the support 13 upon 5 which the device is arranged. The space beneath the bottom 12 is provided to receive a burner of any desired type by means of which the device is heated. The casing may be surrounded by an annular spaced wall 14 providing a heat insulating chamber 15 to mini- 1927. Serial No. 209,476.

tween the upper edge of the casing and the top, as shown in Figure 2. The cover is arranged beneath an internal annular ange 18 of a cap 19, threaded on the upper end of the casing. Thumb screws 2() pass through the flange 18 to securely clamp the top in position, eight of the screws 20 preferably being employed.

The cover is provided centrally thereof with a preferably elongated vertical boss 21 which is internally threaded to receive a threaded stem 22 for a purpose to be described, the stem having a handle 22 at its upper end. Leakage of fluid pressure through the boss 21 may be prevented by packing 23 held in position by a packing nut 24.

A cradle indicated as a whole by the numeral 25 is arranged within the casing. This cradle includes upper and lower plates 26 and 27 respectively, the upper plate preferably being relatively narrow, as shown in Figure 3. The lower plate is preferably circular and the two plates may be secured together by suitable bolts 28. Relatively heavy springs 29 are secured to the upper face of the lower plate 27 for a purpose to be described. One

or more molding flasks 30 may be supported by the lower plate 27, these flasks resting upon the springs 29. The inner wall of the casing 10 is preferably provided with dia- 3 metrically opposite guides 31 to receive outstanding guide flanges 32 carried by opposite edges of the plates 26 and 27. It will be obvious that this construction prevents rotation of the cradle. Vertical retaining rods 32 may be mounted on the sides of the plate 27 to prevent lateral displacementof the flasks. A supporting disk 33 is arranged on the lower end of the stem 22 and may be secured against rotation with respect thereto by a pin 34 or any other suitable means.` Ball bearings 35 are arranged between the disk 33 and the lower face of the plate 26.

Stops 36 are carried by the plate 26 and project upwardly therefrom, these stops l" preferably being provided at their upper ends with heads 37 adapted to engage the top 16, as will be apparent. Means is provided for clamping the flasks together during the vulcanizing operation. As shown in Figures 2, 3 and 4, a plurality of pairs of pins 38 are carried by the head 16 and depend therefrom, these pins being frictionally received. in openings 39 formed in stems 40. 'il he lower ends of each pair of stems 40 are connected by an arcuate plate 41, these plates obviously being arranged on opposite sides of the plate 26, and adapted to engage the upper face of the uppermost molding flask. Each device is equipped with a number of the stems 40 of varying lengths in order that the device may accommodate varying numbers of flasks, as will become apparent.`

A number of raw materials are available for making dental plates, and these materials usually are vulcanizable at different temperatures and pressures. Accordingly, means are provided for operating the device at such different temperatures and pressures to permit the vulcanization of different materials. A suitable thermometer 42 and steam gage 42 are carried by the top 16, and obviously these instruments are adapted to indicate the highest temperatures and pressures at which the device is intended to be operated for vulcanizing different materials. As shown in Figures 1 and 2, the top 16 is further provided with a plurality of upstanding pipes 43 and these pipes are provided with spring pressed blow olf valves 44 and 45 respectively. The spring which seats the valve 44 is preferably lighter than that of valve 45, and the pipe 43 associated therewith is preferably provided with a manually controlled valve 46. The-two valves 44 and 45 permit the device to be used in connection with dental materials possessing two differn ent vulcanizinfr temperatures and pressures, but it will be apparent that any number of blow off valves may be employed, all but the one operable at the highest pressure preferably being provided with valves 46.

The operation of the device is as follows:

"W ith the cover and cradle removed from the casing, together with the stem 22, one or more flasks, with plates in position therein to be vulcanized, are arranged on the springs 29 and the device is assembled. It will be apparent that the lengths of the stems 40 employed will depend upon the number of flasks being used. TNhen a smaller number of flasks are employed, longer stems 40 are used in order that the plates 41 at the lower ends thereof will properly contact with the top of the uppermost flask. A suitable quantity of waiter is placed in the casing to generate steam and the eoverris placed in position` The ring 19 is screwed down against the top 16 and the latter further may be tightened by the thumb screws 20. A burner is then placed beneath the easing inthe manner de scribed to generate steam to accomplish the vulcanizing operation. The stem 22 is rotated by the handle 22 to move the cradle upwardly. The handle is revolved until the top of the uppermost flask contacts with the plates 41 to clamp the flasks together. The burner may be controlled to generate the proper heat and pressure, and when the inaterial beingtreated is vulcanizable at a relatively low temperature and pressure, the valve 46 is opened. rIhe spring associated with the valve 44 is preferably of such a tension as to permit the valve to open when a pressure is reached in excess of that desirable for vulcanizing the material. If the material being treated is vulcanizable at a higher temperature and pressure, the valve 46 is closed to render the blow off valve 45 operative, the spring associated with the latter valve being tensioned according to the vulcanizing pressure of the material. By using the proper number of blow off valves with the springs thereof properly tensioned, it will be apparent that the device is adapted to be operated for vulcanizing plates made of different materia-ls such as rubber, lteco, Hecolite and the like. vWhen more than two blow off valves are employed all must be provided with manual control valves 46 except the one which opens at the highest pressure. As the plates become hot and tend to expand, the expansion is taken up by the springs 29, thus preventing damage to the device and possible injury to the operator due to eX- plosions. The safety of the device also isincreased by the fact that the cradle is moved upwardly to effect the clamping operation, instead of downwardly as is the usual practice. If breakage of the cradle occurs due to excess pressure, the bottom of the cradle will drop instead of the threads of the stem 22 being stripped as often occurs in the usual forms of vulcanizing devices for dental plates. Upward movement of the cradle is limited by the stops 36, and the chamber 15 minimizes the loss of heat units from the casing to provide economy in operation. In the form of the device illustrated, the disk 33 is secured to the threaded stem 22 and rotates therewith, friction between this member and the upper plate 26 of the cradle being minimized by the bearings 35. It will be obvious however, that other means for effecting the lifting action of the cradle may be employed. As the cradle is lifted, the guides 31 and flanges 32 prevent rotation of the cradle thus maintaining it in proper position to permit the plates 41 properly to clamp the flasks.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim l. A device of the character described comprising a vertical casing,` a cradle arranged in said casing and including an upper relatively narrow plate, a substantially circular lower plate spaced therefrom and adapted to support flasks thereon, and a pair of rods connecting said plates and passing through the end portions of said upper plate, means for elevating said cradle, a plurality of'depending pins secured at their upper ends to the top of said casing, a rod having an opening in its upper end to frictionally receive each of said pins, and plates carried by the lower ends of said rods and adapted to contact with the uppermost flask to effect a clamping action thereagainst when said cradle is elevated.

2. A device constructed in accordance with claim l wherein the means for elevating said cradle comprises a threaded stem connected at its lower end to said cradle, the top of said casing being provided with a relatively long internally threaded boss through which said threaded stem extends.

3. A device of the character described comprising a vertical cylindrical casing, a flask supporting cradle arranged in said casing, a vertical stem threaded in the top of said casing substantially axially thereof and connected at its lower end to said cradle, said stem being rotatable in one direction to elevate said cradle, vertical guides carried by said casing, portions of said cradle being associated with said guides to prevent rotation of said cradle when the latter is elevated, and means carried by the top of said casing and adapted to contact with the uppermost flask to effect a clamping action thereagainst.

4. A device of the character described comprising a casing, a flask supporting cradle arranged .in said casing, means for moving said cradle upwardly, means carried by the top of said casing and adapted to contact with the uppermost flask to eect a clamping action thereagainst, a plurality of blow off valves associated with said casing and operable at progressively increasing pressures, and manually controlled cut olf valves connected to each of said blow ofi' valves except the one which is operable at the highest pressure.

5. A device of the character described comprising a vertical casing, a flask supporting cradle arranged in said casing and including upper and lower plates secured to each other, the upper of said plates being relatively narrow, means for moving said cradle upwardly, a plurality of dependingmembers arranged in said casing and detachably connected thereto, said members being adaptedto contact with the uppermost flask to effect a clamping action thereagainst when said cradle is moved WILLIAM MORTON POST. 

